Reboring and grinding machine for engine cylinders



Nov. 24, 1925. A

\ L.E.JORDAN ETAL REQORING AND GRINDING MACHINE FOR ENGINE CYLINDERS 5 Sheets-Sheet 1 Filed Dec. l, 1922 snm 5 v1 NMOM.4 mJMTv mu T mar s 1 Eff M5 M n Nov. 24, 1925- 1,562,969

L. E. JORDAN ET AL REBORING AND GRINDING MACHINE FOR ENGINE GYLINDERS Filed Dec. l, 1922 5 Sheets-Sheet 2 W #Tram/EY. i l

Nov.l 24, 1925. 41562.969

v l.. E. JORDAN ET AL REBORING-AND GRINDING MACHINE FOR ENGINE CYLINDERS Nav. 24, 1925. 1,562,969

L, E. JORDAN ET AL REBORING AND GRINDING MACHINE FOR ENGINE CYLINDERS Filed Dec. l, 1922 5 Sheets-Sheet 4 F Nov. 24, 19`25.

L. E. JORDAN ET AL REBORING AND GRINDING MACHINE FOR ENGINE CYLINDERS Filed Dec. l, 1922 5 Sheets-Sheet 5 Patented Non. 1925.

:BEBER/T JORDAN AND CHARLES SGNORS, BY ASSGiTlifi 'B'IRRG'WS OF MINNEAPOLIS, MINNSOTA, AS- S, TO JPJDAN MACHNE TOOL COMPANY, OF

`MINNEAFCLS7 NNNESQTA, GORPCRATGN 'CSF MINNESOTA.

REBOENG AND GRNJNG MACNE FR ENGINE CYLINDERS.

Application filed December To {zi/Z fro/mm 'if' 72mg/ concern:

lle it `known that We, Lnnnn'r E. Tonnen and (lnimnn's H. il'innows. citizens oli the United States. residing et lllinneapolis, in the county of Hennepin and State ot liv/limiesota. have invented certain new and nsei'nl llinprovelnents in Reborinff; and `Grinding;` llilachines for Engine Cylinders; and we do hereby declare the following` to be a tnll7 clean and exect description ot the invention. such as will enable others skilled in the art to which it apperteins to'niahe and use the saine.

This invention relates to n portable ina-A chine for boring and grinding-` the cylinders of an internal Combustion engine and the niachine is particularly adapted to oe used :is a reborer and grinder. The cylindin's` on .interinil combustion engines.y and especially automobile engines. often `ret ont olli round due to piston wear or becon'ie cnt or scored. y In such cases it really necessary to rebore and grind the ryliniflers to again secure al perfect 'lit ttor `the pistons and piston rings.

lt is an object of this invention, theretore, to provide a` machine ot sin'iple and elicient construction which can be easily operated and which comprises a means for reboring the cylinder, as well as means for grinding the saine.

`it is a further object of the invention to provide such a machine having- :t boringv bar adapted to carry e boring` head, which boring bar has jonrnaled therein ay grinder carrying;` member, said boring` ber and grinder carrying ineinber being;` capable of lonnitnihnal feeding; movement in two directions. y lt is also an object ot the invention to have said grinder carryiigrneniber disposed eci-eiitrically in the boring bar with means lor varying;` said eccentricity.

llt isst-ill a `further object ol the invention to provide such ay machine having a inotor driven shaft and separate driving ineens geared to said shaft for independently driving said boring;l bar and said, grinder carryinl;r ineinber respectively.

rllhese and other objects oli the inventioii, inolndinn the novel feeding` arraneenients, wili he nlly lorth7 together With the adinntageL-i oi the invention in the Ztolloiving l, 1922. Serial No. 604,397.

description made .in connection with the aecoinpenyinfr drawings in which like relierence clni-racters refer to the sinne parts throughout the dili'erent views. and in Whicl'i, l

Fig. l a view `in side elevation o'l" the machine;

`Fig. 2 is a central vertical section. taken Isiibstantially on the line 9,-2 of Fig'. l. a vportion of the boring bar beingf shown .in side elevation; Y

Fig'. 3 is a horizontal section taken substantially on lines 3 3 of Fig. l end Fig. 4l. as indicated by the arrows; 4 1

y Fig. i is a vertical section taken on the line ile-1i oit Figi. 3, as indicated by the arrows Figi'. 5 is a horizontal section taken on the line SM5 of Fig. 6, as indicated by the arrows Fig'. 6 is a. vertical section ,taken on the line 6 6 et Fig. 5;

Fig. 7 is a horizontal section taken snbestantielly on the line 7-7 of Figs. l and 8, as indicated by the arrows;

Fi 8 is a section taken on the line 8-8 of Fig. 7, as indicated by the arrows;

Fig. 9 is a fragmentary horizontal seetion showing; a inodlicetion of the l-eedine` mechanism. for the boring` bar;

Fig. l() is a vertical section taken on the line lll-l0 of Fig. 9, as indicated by the arrows Figfll is a bottoni plan view of the bor- .inghead used;

Fig. 12 is a vertical section taken on the line Y12412 of' Fig. ll; and Fig. is a, if'erticail section taken on the line 'lh-13 or' Fig. 1l. l

Referring` to the drawings, Athe machine comprises a- 'liraine having a base portion l; which portion is Vifinished at its lower side and adapted to rest on the cylinder block oit the engine. This base portion has a, pedestal portion on `which is mounted a` suitable inotor 2 shown as zi conventional type of electric motor. Tlhe traine lso has a grearinpgenclosing portion 3 andanlipstanding; casing portion l forming the upper bearings and enclosure for the boring ber. A boringber 5 is jonrneled in the portion i oi'? the traine, 'which 'traine will be provided with suitable spaced bearings in which said bar .tits and rotates. The bar 5 is provided with a spline-d groove 6 extending toI point-s adjacent each end of the bar and an annular gear or ring 7 surrounds the bar and has a tongue or key itting in the groove G. The ring 7 is formed at its lower portion with gear teeth 8 and thus forms a worm wheel gear and said ring is provided at points above said teeth with a pair of project-ing teeth 9 for a purpose to be later described. Said teeth 8 are engaged by a worm gear 10 secured on a shaft 11 extending transversely of the frame portion 3 and journaled in suitable bearings therein, which shaft carries, adjacent one end and in the casing, a gear 12. The gear 12 meshes with and is driven by a gear 18 secured to the motor shaft 14e, which shaft is shown as provided with a suitable coupling member 15 adapted to be bolted to the motor 2. It will also be noted that the gear 13 on the motor shaft 1% is provided with a grooved collar receiving a fork 53 having a handle 54 extending through the casing portion 3 and guided in a slot therein and an exterior lug thereon. lly moving the handle 54, gear 13 can be moved out ot mesh with gear 12 and the drive to the boring bar 5 discontinued. rlhe shaft 11 projects at the side of the trame opposite the motor and is provided with a squared or angular shaped portion 1.6 adapted to receive a suitable c ank or wrench by which the shaft may be turned and the boring bar thus manually rotated. The lower portion ot the bar 5 is bored and threaded, as shown at 17, for the purpose of having secured therein a boring head to be later described. n

The bar 5 is provided with an eccentric bore and a sleeve 18 is journaled in this bore in the ba1 and has its axis disposed eccentrically to the axis ot the bar. A member 19 is disposed in the sleeve 18 eccentric therewith and this member has an expanded or cene shaped portion 20 at its lower end journaled in a bushing 21 secured in the lower end of sleeve 18. This portion 2O oit.' the member 19 is also provided with a tapered socket in which the tapered shank or' a grinding wheel 22 is adapted to be secured. rlhe upper end ot the bar 5 is threaded and receives a threaded sleeve coupling 23, having an inwardly extending' flange extending over a collar or liange 24 formed on the upper end of sleeve 18 so that the said sleeve 18 is thus firmly supported and held in fixed relation to the bar 5, the upper end of said sleeve being substantially i'lush with the upper end of the member 23. Ilhe member 19 has a reduced portion 25 adjacent its upper end, at each end of which are oppositely facing conical portions 26. The lower part of the portion 25 and the lower threaded sleeve 27 which is screwed into the top of the sleeve 18. This sleeve 27 is also interiorly threaded and receives therein another exteriorly threaded sleeve 28, in which the upper part ot portion 25 and the upper conical portion 26 are journalcd. The sleeves 27 and 28 are provided with angularly shaped flanges at their upper portions and jam nuts 29 are threaded thereon beneath said flanges for holding the sleeves in any fixed adjusted position. It will be seen that the sleeves 27 and 28 torni a take-up device for the member 19. Said member has a shoulder portion immediately above the upper conical portion 26 which receives a. link L10 to be later described and above this link, a pinion 81 is secured to the reduced end of the member 19, said pinion being surmounted by another link 410. The upper portion ol the sleeve 18 is provided with teeth 82 to form a worin wheel, which teeth are engaged by a worin member 33 secured to a short shaft 311- l journaled in the upper part of bar 5, and a bushing threaded into said bar. 'lhe shait 84j is provided at one end with a squared or angularly shaped portion adapted lo receive a socketwrench or crank which may conveniently be inserted through an opening Sti in the casing portion el. rlhe eccentricity olf the sleeve 18 in bar 5 is the saine as the eccentricity o'lz the member v19 relative to the sleeve 18. It will thus be seen that. by turning the shaft 341 and revolving the sleeve 18, that the axis oli ineinbor 19 may either be brought into concentric relation with the bar 5 or, in other words, coincident with the axis ol the bar 5, or this axis ot' member 19 may be olllsct tlrom the axis oit the bar 5 a distance equal to twice the ececntricity between the sleeve 18 and bar 5.

The pinion l1 and `grinder carrying ineinber 19 are driven by a gear 37 secured on a short shaft P58 which is carried in :i pair ot links 39 and this shaft is connected to the upper portion of the member 19 by a pair of links ll() disposed just inside oit the links 39 and iinn'wdiately above and below the pinion 81. The links 39 are swingingliY connected at their other ends to a shal't fll which. is journaled at its upper end in the top portion 4l ot the traine and at its lower end in spaced bearings in the portion is of the frame. Between the links 39, a gear l() is secured to shaft 41 and immediately above and below the links 39 are the arms ot a yoke member 4t2. rlhc member 42 has a portion extending downward parallel to the shaft 11 which is connected to an annular member or rin;r 48 surrounding the boring bar 5 and fitting in an annular recess made therein. This ring 43 has an extension 15. tornilll) ling a lnutengaging a screw d6 te be 4later described and thisextension has aatongue 4:7 extending into and `through a slot t8 yformed .in `the side of the vertical portion d el the traine. It will also .be noted that the lewe arm-.of the ylie '4t2 extendedfto form la support Lfor the lower `li-nlc 99, thus afernaadjacent its lowerfend which meshes Vwith the gear -59 secured to 'the motor shaft del, the gears 49 .and 50 being illustrated as helical gears. @It niay die Vhere noted the gear L5() is provided with .a groovedacollar reeeininga vfork 511 :having aa handle 52 extended :through ithe 1 casing portion and adapted ite yslide .in a slot `therein and an exterior lug thereon. :By #inox/ing the handle 52 longitudinally, gear 50 may be disengaged from gear Lt9 andithe drive tolthe member 19 diseo-ntinued.

The screw d6 above vreferred to is journaled :at its ltop .portion in a bore in the `upper part 4rof the traine `and is journaled at its llower yend in bearings inthe portion 3 el the liranie, as shown in Fig. 8. This screw `has splined thereto adjacent its lower end,za gear avhicli gearis provided with a grooved eollarG at one -sifdefthereof and Illa-s a sleeve extending at its .otherfside carrying a star wheel 557 at its lower end. A. short slnriith parallel iwith the screw d6 is journaled :adjacent `tliereto Iin the .portion -g) Aoit the traine, as shown in Fig. 8 and this shaft `has splined `thereon a gear 59, which gear also h as-a groovedcollar (50 at its upper side and a short sleeve at vits lower side having a staravheel Gl atithe end thereof.

The ygrooves andcollars :Wand (30 are engaged `by a bleek (52 having `a hand vlever (33 pivoted thereto, ywhich. hand lever 4entends fthrough Van opening :in `theacasing portion 3 `and is `pivoted in lugsndjacent said opening. llit lwill :be seen fthat by `moving Jthe @lever G3 the gears 55 and 59 will be.siniultaneonsly nioved vertically. By this movement, the teeth of either star wheel 57 or Gl ean be inoved into alineinent with the teeth 9 on the Worin -vvheel ring 7 which is on the boring bar The ger s 55 and 59 and the star wheels 57 and lil can also ybe `inoved so that the 'teeth 9 pass between the star wheels. It will `be noted that when lone of the star wheels is engaged by the :teeth 9 on Worin wheel -7 the screw d6 `will be turned in one direction and When the peints on the other star wheel are engaged by said teeth `9 the screw Will @be turned in the opposite direction. The screw i6 is also provided iniinediately above the easing .portion 3 With a `to-nsetwotools 74 of dove-tailed shape 4.which beveled gear Gd- Whieh isengaged by another beveled gear secured to a shaft :66 extending throngh .the easing Iportion 3 4and :provided with a crank G7. By turning `the crank handle 97, screw Llcan thus .beananually turned toraise and loWerthe `member d3 through its extension 45 which `is in en gagen'ient with said screw. It will be noted that the bar 5,;1ne1nber 43,' .lf2 and the parts carried thereby" ineludingthe gears 37 and 30 are all inov'ed vertically when thescreW d6 is'tnrned.

,In Figs. l1 `to 13, a boring head 68 is shown having a :threaifled.sleeve 69 thereon adapted nlo die screwed Vinto the threaded bore l7 of the `bar 5. rlhe lneniber `(38 :is provided `vvith a dove-tailed groove 70 `in Which slidesrand 'tits a `portion of a `Wedge member 7 L `.bored .and threaded `to be lengaged by a screw 72 journaled inthe inein- VberoS and provided Witha'greoved head S5 disposed in the recess in theonter side ret ineinberi, said screw 72 being held in place n 4by' a collar 7 3. The boring head is designed Vare :held in place by theelainping plate 75 secured in .the head `.by screws. rl-he yinner ends of the tools :bear against the wedge portion of theineinber 7l anchas is obvious, can :be inoved outwardly `by `moving'said `wedge `portionby lmeans of sthe screw 72.

ln Figs. 9 and l0, a inodilied l'orln of `shi-tt structure is shown in the gears `which :operate the serew 4:6. lin 4said figures, the worm wheel ring 7 having thereon `one of `the teeth 9 is shown. The shalt 79 secured in the Aflower portion 3 off the Ytraine and vthis shaft carries a gear 77 corresponding to the gear 59 on shaft 5S yin Fig. 8. The gear 77 meshes `with agear 78 and both gears are iprevided with hubs or sleeves disrposed between .the plates or `arins 79 of a shitting yoke SO which is extended .tln'ough the `casing 3 in the forni et a handle and has pivoted thereto, a spring pawl 8l `having `a portion adapted ('oengage in any one of three holes 82 ina boss on the side et theeasing. The gears 7 7 and v78 also eaizry -star `wheels 83 and 8:1-, respectively, located Vat different' distances treni sa id gears. lVhen the lpawl 8l engages in the middle yaperture 82 the star Wheels are in such vposition rthatthe tooth 9 engages neither. `W hen the `paivl is in either one ofthe other apertures 82, however, one et the star `Wheels will be in pesi tion to be engaged by the toothv `9 on the Worin wheel ring 7 so that the screw Will be driven in one direction or the other.

In will be ynoted that the portion 4L et the lf'an'ie adjacent the slot 48 is provided with graduations `to indicate ythe extent of travel el' the boring lbar 5 and parts carried `thereby. 4

lin operation, .the frame will', as stated, be placed in position on theeylinder bleek et the engine. The boring bar will then be centered over one of the cylinders by the use oit a centering cone or other centering means placed in the bar. lVhen the said bar is thus centered, the 'frame will be firmly secured on the block and the tools 74 set a proper distance to give the desired bore of the cylinder. The motor will then be started and the boring bar and boring head driven. lt will be understood that at this time the boring head is in place in the bar and the grinding wheel 22 is removed therefrom. Gears and 59 will now be set so that the screw lo is turned in the proper direction to feed the boring bar downwardly, and the clutch handle 52 will be moved to disconnect the drive for the grinderl carrying member 19. The motor now being started, the boring bar will be rotated through shaft l1 and worm 10 and fed down through the cylinder so that the cylinder will be properly bored or rebored. lWhen the boring head has traversed the desired distance into the cylinder the feed of screw 4G can be reversedby movement oi' the gears 55 and 59 by leverf and the head thus fed out of the cylinder. After the cylinder has been bored the boring head will be removed from the boring bar 5 and the grinding wheel 22 and its carrying member disposed in the member 19. The shaft Si and worm 33 will now be adjusted to bring` the edge ot the grinding wheel 22 in proper relation to the bored cylinder surface to properly grind the same. Gear 5() will now be moved into engagen'lent with gear 49 and the meinber 19 driven through shaft il and gears 30, 37 and 3l. The grinding wheel 9,2 will Y thus be driven at comparatively high speed and will be `carried around in proper relation'to the inside ot the cylinder by the slow rotation ole the boring bar. rlhe bar will, at the saine time, be ited downward through the cylinder by screw lli and the leed et the screw can be reversed at the proper time to again tred upward. The inside of the cylinder will thus be properly ground and'linished. The amount ot the vfeeding movement can; it' desired, he ascertained `from the graduations on the Yportion 4lol the 'lran'ie Any wear or looscness oceurring in the lower portion 2() ot the mon'iber l?) can be accurately taken np by adjustnient ot thesleeves S27 and 28. Villien it is desired to quickly raise or lower the borin head or the grinding wheel, this can be readily donc by operation ot the crank handle 6T. As before stated, the-griinling wheel 22 can be presented so that it is concentric to the boring bar. or it may be at any intermediate position between the concentric position and its extreme position ot eceentrieity. After one cylinder of the engine is bored and ground, the machine can be shifted and the boring bar 5 alined escaneo with another cylinder. After this cylinder is finished, the machine may be swung through 180 degrees and alined with the next cylinder', it desired. Such a turning movement is usually made in a four-cylinder engine, two of the cylinders being ground while the machine is in one position and two with 'the machine in another.

lilith the modified form oit shift shown in Figs. 9 and 10, the star wheels for operating` the screw 4:6 will be shifted by the yoke 80 instead of by the lever 63.

From the above description it is seen that applicant has provided an extremely simple, compact, convenient and ellicient machine for operating on the cylinders of internal combusition engines. The machine is entirely self-contained and the various adjustments thereol are easily and conveniently made in a positive manner without the use ol any objectionable belts. The machine is designed to be used in garages and automobile repair shops and is conveniently transportable tor such use. The parts of the machine are all securely heldin position and when once assembled there is 11o tendency tor any of the parts to become disarranged.

lt will, ot course, be understood that various changes may he made in the form, de-

tails, arrangement and proportions olf the 'f parts without departing from the scope ot applicants invention, which, generally stated, consists in the matter shown and described and set forth in tlieappended claims.

lWhat is claimed is:

l. A portable machine for grinding and boring the cylinders olE internal eon'ilnlslion engines having in con'ibination, a vtrame constructed and arranged to rest on the engine casing, and. comprising bearings, a boring bar revolnble in said bearings and longitndinally movable relative thereto, a niember surrounding and splined to said boring bar ttor turning the same, a grinding inember eccentrically disposed in said boring bar, means tor turning said grinding member, a screw journaled in said trame parallel to said boring bar adapted to move said boring bar and grinding member longitudinally, means driven by sai-:l member surrounding the boring bar for turning said screw in one direction. and another member driven by said means snrrouiuling the boring liar adapted to be shifted into position to drive said screw in the opposite direction.

2. A machine 't'or grinding and boring the cylinders of internal combustion engines having in combination, a iframe, a rotatable boring bar in said frame, a sleeve eccentrioally journaled in said boring bar, a grinder carrying member disposed in said sleeve, means iifor rotating said sleeve te vary the eceentrieity of the axis o'l' said grinder carrying member relative to the axis oli said boring bar a gear secured to said grinder lll() carrying member, a driving` shaft for said member extending parallel to said boring bar, links pivotally connected to said grind-- er carrying` member and shaft to swing about the centers thereof, a shaft to which the other ends of said links are pivotally connected, a gear on said latter shaft and a gear on said driving` shaft meshing with both of said 0earswhereb\ said (Years will b l O remain in mesh when said sleeve is turned.

3. A machine for grinding and boring the cylinders of internal combustion engines having in combination, a frame, a rotatable boringbar in said frame, a grinder carrying member movable eceentrically to said boring bar, a gear at the top of said grinder carrying member, a driving shaft for said member parallel to the axis thereof, a gear on said driving shaft, an idler' gear meshing with said gears and a swinging compensat ing means carrying said idle gear whereby said gears will remain in mesh when said grinding member is moved ecccntrically to said boring bar.

ll. The structure set forth in claim Q, a yoke on said driving` shaft embracing the ends of said links, said yoke, links and gear on said. drivingshaft being splined thereto and an extension on said yokeembracing said boring bar and movable therewith.

5. A portable machine for grinding and reboring the cylinders of internal combustion engines having in combination, a frame adapted to rest upon the engine cas-ing, a rotatable boring bar journaled and movable in said frame and having means at its lower end for detachably receiving a cutting tool head, a grinder carrying member eccentrically journaled in said bar, a grinder removably carried by said member beneath said boring bar, means for tlnning said member to vary the distance between the axes of said boring bar and grinder, -and means for moving said boring bar and grinder in both directions vertically on said frame.

G. A portable machine for grinding` and boring the cylinders of internal combustion engines having in combination, a frame comprising bearings, a rotatable boring bar journaled in said bearings and longitudinaL ly movable relative thereto, a grinder earrying member eceentrieally journaled in said boring bar and rotatable therein to vary the distance between its axis and the axis of said boring bar, a motor on said frame, a driving shaft driven from said motor, means for driving said boring bar from said driving shaft, and means for driving said grinder carrying member from said driving shaft.

7. The structure set forth in claim 6, said means for driving said boring bar being disposed adjacent the lower end thereof, and said means for driving said grinder car- ,eee r3 rying member being disposed adjacent the upper end thereof.

8. A portable machine forrgrinding and boring the cylinders of internal combustioir engines having in combination, a fra-.me `constructed and arranged to rest on the engine casing, a rotatable boring bar insaid fra-me,

a driving shaft, a member surrounding said i boring bar and splined thereto forrotatingu said boring bar driven by said driving shaft, a screw journaled in said frame parallel to said boring bar, a nut member on said screw embracingsaid bar, and means actuatedby said member surrounding said boring bar adapted to turn said screw in either diree tion to move the boring bar longitudinally. and comprising a shiftable member.

9. A portable machine for grinding and boring the cylinders of` internal combustion engines having in combination, a frame, a rotatable boring bar in said frame, a grinder carrying member therein having its axis eccentric to the axis of said boring bar, a shaft, jonrnalediin saidifraine` parallel to said boring bar for driving saidfmember, a motor shaft jonrnaled in said frame for driving` said first mentioned. shaft, a`

shaft geared to said motor shaft, an annular gear surrounding and splined to said bor ing bar, and means on said. last mentioned shaft for driving said annular gear and boring bar.

10. A portable machine for grinding and boring the cylinders of internal combustion engines havino in combination, a frame, a rotatable boring bar in said frame, a grinder carrying member therein, having its axis parallel to the axis thereof, a motor shaft, a shaft geared to said motor shaft and extending parallel to said boring bar, and geared to said grinder carrying member for rotating the same, a shaft geared to said motor shaft and to said boring bar for rotating the latter.

1].. A portable machine for grinding and boring the cylinders of internal con'iliustion engines having in combination, a frame, a rotatable boring bar in said frame, a driving shaft, an annular gear sin'rminding said boring bar and splined thereto driven by said driving shaft, a screw extending parallel to said boring bar, means connected to said boring bar engaging said screw, a star wheel carried thereby, another star wheel geared to said star wheel to rotate oppositely thereto, and means on said annular gear for contacting and rotating either of said star wheels to rotate said screw and move the boring bar longitudinally.

12. rlhe structure set forth in claim 11, and means for moving said star wheels so that either one of the same are in position to be engaged by the means on said annular gear or into position so that neither are so engaged.

13. A machine for grinding and boring the cylinders of internal combustion engines having in combination, a frame, a rotatable boring bar in said frame, a grinder carrying member having a conical portion at its lower end journaled in said boring bar, said member having oppositely disposed spaced conical portions adjacent its upper end and longitudinally adjustable means contacting said conical portions respectively for taking up any longitudinal movement in said member, and maintaining said conical journals in proper position.

14. A machine for grinding and boring the cylinders of internal combustion engines having in combination, a frame, a rotatable boring bar in said frame, means encircling said bar to drive the same, a sleeve eccentrically journaled in said bar, a grinder carrying member eccentrically journaled in said sleeve means for rotating said sleeve to vary the eccentricty of said member' to said boring bar, a screw for feeding` all of said parts longitudinally and means driven :from said tirst mentioned means including a shiftable member for turning said screw in either direction.

l5. A portable machine for grinding and reboring the cylinders 0'1" internal combustion engines having in combination, a trame adapted to rest upon the engine casing, a rotatable boring bar journaled and movable in said frame and extending throughout the greater part of the length thereoi and having means at its lower end tor detachably receiving a cutting tool head, a motor disposed at the lower side o'l' said frame and means adjacent the lower side of said frame driven by said motor for turning said boring bar, a grinder carrying member eecentrieally journaled in said bar, a grinder movably carried by said member below the lower end of said boring bar, and means adjacent the top of said frame for driving said grinder carrying member, and

also driven by said motor.

In testimony whereof we ailix our signatures.

LEBERT E. JORDAN. CHARLES l-l. BURROW 

